#3549 fix

git-svn-id: http://dev.geogebra.org/svn/trunk/geogebra@27674 23ce0884-8a58-47d3-bc5c-ddf1cd5b9f9e
Make sure Undo / Redo over API repaint the views in Touch (needed for Win8 app)

git-svn-id: http://dev.geogebra.org/svn/trunk/geogebra@27675 23ce0884-8a58-47d3-bc5c-ddf1cd5b9f9e
#3164 improvement

git-svn-id: http://dev.geogebra.org/svn/trunk/geogebra@27676 23ce0884-8a58-47d3-bc5c-ddf1cd5b9f9e
Ticket #3485: undone some changes which are suspected to slow things, until their full potential is used

git-svn-id: http://dev.geogebra.org/svn/trunk/geogebra@27677 23ce0884-8a58-47d3-bc5c-ddf1cd5b9f9e
Allow HTML in descriptions

git-svn-id: http://dev.geogebra.org/svn/trunk/geogebra@27678 23ce0884-8a58-47d3-bc5c-ddf1cd5b9f9e
Do not allow 0x0 materials in GeoGebraTube

git-svn-id: http://dev.geogebra.org/svn/trunk/geogebra@27679 23ce0884-8a58-47d3-bc5c-ddf1cd5b9f9e